

(ORTHORRHAPHA BRACHYCERA.) 



ORTHOGENYA. 



Empididae. 



Head rather small, more or less globular and more or less arched 

 behind ; sometimes the occiput drawn conically out and the head more 

 or less pear-shaped; it is almost equal to the breadth of Ihorax or a little 

 narrower. Occiput has bristles or hairs. The vertex bears three ocelli 

 and generally small ocellar bristles. Eyes large, generally bare, some- 

 times hairy; they are either touching in the male and separated in 

 the female, or touching in both sexes, or finally more or less sepa- 

 rated in both sexes; in the last case the frons is sometimes narrower 

 in the male than in the female. When the eyes are touching in the ^ 

 male, the facets are in this sex larger above than below, and when 

 touching in both sexes, the facets are larger above in both sexes. 

 Sometimes the eyes are touching below the antennæ. In the middle 

 of the inner eye-margin there is always an incision which may be 

 larger or smaller, sometimes very small and shallow, but always per- 

 ceptible. The antennæ are inserted near to each other, in or about 

 in the middle; they are three- to- five-jointed ; the two basal joints 

 are generally short, the first sometimes somewhat elongated; the third 

 joint is longer, compressed but otherwise of somewhat variable shape, 

 from short ovate to somewhat long and band-shaped ; it terminates 

 in the five - jointed antennæ with a style or a longer arista , both 

 being two - jointed with a short basal joint ; in the four - jointed an- 

 tennæ the arista is undivided, and in the three-jointed antennæ the 

 third joint tapers into or bears an arista which is not jointed and 

 not articulated to the third joint, but forms in connection with this 

 an undivided joint. The jowls are very small or not at all developed, 

 rarely longer and descending below the eyes. Epistoma is broader 

 or narrower, generally narrow, and, when the eyes are touching below 

 the antennæ, very small. An oral cone is present but small; some- 

 times, as in Clinocera, Dolichocephala and Chersodromia there seems 

 to be no real oral cone present. Clypeus is generally more or less 



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